The office of Michigan's chief executive said he issued the declaration Tuesday "due to the limited availability and temporary shortages of gasoline and diesel fuel." The order suspends state and federal regulations on hours of service for motor carriers and drivers transporting gasoline, diesel fuel and jet fuel.

"This energy emergency declaration is necessary to ensure that petroleum supplies will remain sufficient and to assure the health, safety and welfare of Michigan residents and visitors," Snyder said in a statement.

The shortage follows a shutdown of the West Shore Pipeline, which runs between Milwaukee and Green Bay, Wis. A leak was detected in the pipeline July 17 near Jackson, Wis. Rockford, Ill.-based West Shore Pipeline Co. owns the pipeline and made repairs, allowing the flow to resume last Saturday.

The pipeline is the source of gasoline and diesel fuel to service stations throughout the western and central Upper Peninsula, and Snyder's office said Thursday that shortages continue this week. Carriers have been seeking alternate terminals and face more difficult delivery operations, the office said.

Wisconsin Gov. Scott Walker last week issued an emergency proclamation for northeastern Wisconsin. That proclamation also allowed drivers of gasoline trucks to be exempted from weekly hours-of-service restrictions on all state highways for 10 days, effective last Saturday.